Volume 30 (2018): Issue 2 (December 2018)

Optimal feeding of field-grown plants is thought to be a key factor modifying their growth and development. Natural biostimulants, foliar fertilizers and plant growth regulators have been applied in horticultural production; however, their effect varies depending on the plant species treated, and those have been mainly cucumber, tomato, pepper, potato, and melon. The aim of the study was to evaluate the effect of preparations produced through nanotechnology on the yield and fruit quality of sweet pepper grown under cover. The experiment comprised plants grown in three different combinations: combination I (plants treated with 2 kg ha⁻¹ Nano Active); combination II (plants treated with 1% Nano Active Forte + 4 kg ha⁻¹ Nano Active Forte + 2 kg ha⁻¹ Nano Active, a single treatment carried out at the initial stage of fruit formation); and combination III (the control, where all plants were sprayed with water).

The obtained results showed that Nano Active Forte foliar treatment of sweet pepper plants significantly increased fruit yield in protected cultivation. Supplementation with foliar fertilizers modified the fruit chemical composition. Application of the Nano Active Forte preparation led to an increase in dry matter content as well as in the concentrations of total sugars, vitamin C and carotenoids. Applications of Nano Active Forte and Nano Active enhanced the potassium and phosphorus contents, while the concentrations of nitrates and calcium remained at the same level regardless of the preparations used.

There are about 40 species in the Pleurotus genus, including those with high economic significance, i.e. P. ostreatus and P. pulmonarius. The fruiting bodies of oyster mushrooms are of high nutritional and health-promoting value. In addition, many species belonging to the Pleurotus genus have been used as sources of substances with documented medicinal properties, such as high-molecular weight bioactive compounds (polysaccharides, peptides and proteins) and low-molecular weight compounds (terpenoids, fatty acid esters and polyphenols). The bioactive substances contained in the mycelium and fruiting bodies of Pleurotus species exhibit immunostimulatory, anti-neoplastic, anti-diabetic, anti-atherosclerotic, anti-inflammatory, antibacterial and anti-oxidative properties. Their multidirectional positive influence on the human organism is the result of interaction of bioactive substances. Extracts from individual Pleurotus species can be used for the production of dietary supplements increasing the organism’s immunity. They are also used for the production of cosmetics. They can be added to functional foods as probiotics, or used as natural preservatives or ingredients of special foodstuffs for patients with specific diseases.

The aim of the study was to replace mineral fertilizers with organic and biological fertilizers to improve nutrient uptake, plant growth and the concentrations of some important secondary metabolites in periwinkle (Catharanthus roseus L.). Periwinkle plants were grown under different rates of N supply (0, 20 and 40 mg kg⁻¹ soil) and biological treatments (Azospirillum, Azotobacter, Azospirillum plus Azotobacter, Azospirillum plus fungal compost, Azotobacter plus fungal compost, and fungal compost). The concentrations of pigments and nutrients were measured by spectrophotometry and flame photometry. Secondary metabolites were analyzed by high-performance liquid chromatography (HPLC). Data were recorded for plant growth and development parameters, nutrient uptake and some secondary metabolites of periwinkle plants. The results showed that the N-fertilizer and biological treatments significantly improved most growth attributes and nutrient uptake and increased the concentrations of secondary metabolites as compared to the control. Maximum concentrations of root ajmalicine (0.54 mg g⁻¹ DW), leaf vinblastine (0.96 mg g⁻¹ DW) and root catharanthine (2.38 mg g⁻¹ DW) were obtained from the treatment with Azospirillum under N-fertilizer at 20 and 40 mg kg⁻¹ soil. Azotobacter along with fungal compost under N-fertilizer at 40 mg kg⁻¹ soil induced the maximum concentration of leaf vindoline (1.94 mg g⁻¹ DW). The highest concentration of root alkaloids (1.11 mg g⁻¹ DW) was obtained from the treatment with compost under 40 mg N kg⁻¹ soil. Azospirillum, Azotobacter and fungal compost combined with the N-fertilizer improved many morphological and nutrient characteristics. In conclusion, the growth and metabolism of C. roseus were significantly positively affected by the organic and biological fertilizers.

Fenugreek (Trigonella foenum-graecum L.) is a valuable medicinal plant, which is widely distributed throughout the world. It has been known that plant growth promoting rhizobacteria (PGPR) have positive effects on the quality and quantity of medicinal plants under different soil water levels. For this reason, a factorial experiment was conducted on the basis of a randomized complete block design (RCBD) to evaluate PGPR effects on the morphophysiological and phytochemical traits of fenugreek under different soil water levels. This study was conducted in two separate experiments: after the six-leaf stage and after the flowering stage. In the experiments, the treatments were plant growth promoting rhizobacteria (PGPR) including the control, Sinorhizobium meliloti, Pseudomonas fluorescens, a combination of S. meliloti and P. fluorescens, and different soil water levels (i.e. 100, 80, 60 and 40% of field capacity (FC) in three replications. The results showed that the highest seed weight per plant was obtained by inoculation with the S. meliloti and P. fluorescens combination at 100% FC after the two developmental stages. The maximum concentrations of nicotinic acid and trigonelline were observed for the combination of S. meliloti and P. fluorescens at the soil water content of 40% FC after the six-leaf stage and for S. meliloti at the soil water content of 40% FC after the flowering stage. The correlation and stepwise regression analyses showed positive effects of PGPR application on the morphophysiological and phytochemical traits of fenugreek plants under different soil water levels.

Biblical gardens have existed in the public space for almost 80 years, and yet still up to this moment no scientific definition of this type of garden layout has been developed, nor has any detailed characterization of them been published. Multifaceted, interdisciplinary research carried out in the years 1996-2017 made it possible to gather detailed data pertaining to 63 biblical gardens all over the world, primarily including the oldest ones. The fundamental characteristics of existing sites were determined on the basis of these results, including their naming in different languages, presentation through a logo and motto, plant selection along with the manner of its presentation, the symbols that they employ, street and garden furniture being used and the arrangements of miniature landscapes. An in-depth analysis of the material that had been gathered made it possible to formulate a scientific definition of a biblical garden as a specific type of greenery arrangement. The specifics of biblical gardens lie in the fact that they possess significant semantic value and are an illustration of the sacred texts of the Bible, one of the greatest works of literature. Various artistic works are being used in their arrangement, in addition to modern forms of design, which highlight sensory values through referring to the senses: sight, touch, hearing, smell and taste.

Phenolic compounds are widespread in berries and determine their antimicrobial activity. The aim of our study was to establish the amounts of phenolic compounds and the anthocyanin composition in berries of four Ribes species, and to evaluate the effect of berry extracts on the growth of common Gram-positive and Gram-negative bacteria, and also yeasts isolated from food processing plants. The phenolic content and anthocyanin composition were estimated spectrometrically and by HPLC, respectively. The highest amount of phenolic compounds, and also anthocyanins, was found in extracts of R. aureum ‘Corona’. The anthocyanin content was the lowest in berries of R. aureum Au Gs-5, with equal amounts of delphinidins and cyanidins. Delphinidins were predominant (68.6%) in berries of R. nigrum ‘Ben Tirran’, while cyanidins dominated in R. uva-crispa. The berry extracts of R. aureum Au Gs-5 and R. uva-crispa ‘Lûðiai’ had the largest growth-suppressing effect on yeasts and most of the bacteria tested. All of the berry extracts suppressed the growth of pathogenic and conditionally pathogenic bacteria. The industrially important Lactococcus lactis was the most resistant to the Ribes berry extracts. There was no correlation between the amount of anthocyanins in the extracts and their antimicrobial properties. Extracts with a lower anthocyanin–to-phenolics ratio more effectively inhibited the growth of bacteria.

The aim of the study was to develop an efficient micropropagation system for Rosa ‘Konstancin’, an interspecific hybrid between R. rugosa and R. beggeriana, whose fruits have high pro-health value. Shoot cultures were initiated from shoot buds collected in May and August from 15-year-old field-grown Rosa ‘Konstancin’ shrubs. The effect and interaction of different concentrations of phytohormones, sucrose and iron sources on in vitro initiation, multiplication and rooting of shoots were studied.

The time of collecting explants from donor plants significantly affected the initiation of shoot culture of Rosa ‘Konstancin’. Considerably higher frequency of bud break (100%) was obtained in explants isolated in August as compared to those collected at the end of May (30%). All buds developed into single shoots after 2-4 weeks of growing on the basal Murashige and Skoog medium containing 2.2 µM BAP, 0.3 µM GA₃ and 88 mM of sucrose. The highest multiplication rate (4.8 shoots/explant) in a 5-week period was obtained on MS medium containing 50% of nitrogen salts, 3.1 µM BAP, 0.9 µM GA₃ and 58 mM sucrose. High rooting frequency (100%) and quality of rooted plantlets was obtained on a medium containing 0.5 µM IBA, 138 µM Fe-EDDHA and 88 mM sucrose. Fe-EDDHA had a beneficial effect on the growth and photosynthetic activity of Rosa ‘Konstancin’ plantlets, which were successfully acclimatized ex vitro, with a more than 90% survival rate.

Replant disease refers to the result of monoculture-continuous repetitive planting of congeneric crops or coordinal crops in the same soil for many years. Such disease is recognized as one of the main limiting factors affecting plant growth and production of horticultural plants in many countries. As a result, replant disease in horticultural plants has become a world problem in agriculture and also a bottleneck restricting the sustainable development of agriculture. In general, replant disease results in unfavorable growth of horticultural plants, which is due to allelopathy, autotoxicity, and the imbalance of both soil physical-biochemical traits and soil microflora. An environmentally friendly contribution to this could be bio-controlled by beneficial microorganisms. Arbuscular mycorrhizal fungi, one of soil-inhabiting fungi, can form a symbiotic association in roots to mitigate the negative effects of replant disease in many horticultural plants. Moreover, arbuscular mycorrhizal fungi do not produce any environmental pollution in soils and are a potential biological control. The soil fungi could regulate better morphological, physiological and molecular levels in plants to respond to the disease. This review mainly outlined the current knowledge in mycorrhizal mitigation of replant disease in horticultural plants, which appears to be a promising strategy to improve growth of horticultural plants in replant soils.

The present study reports an efficient in vitro propagation system for Turnera ulmifolia using nodal segments as explants. Turnera ulmifolia (Passifloraceae) is an important garden plant with multipotent medicinal values. Effective shoot proliferation was achieved on agar gelled MS medium (Murashige and Skoog, 1962). The maximum number of shoots (8.3 ± 0.57) per initial explant was obtained on MS medium supplemented with 8.88 mM of 6-benzylaminopurine (BAP) and 0.54 mM of α-naphthalene acetic acid (NAA). The highest number of shoots (59.5 ± 2.10) proliferated on semi-solid MS medium (with agar) augmented with 2.22 mM of BAP and 2.32 mM of kinetin (Kin) along with 0.54 mM of NAA. Longer (4-5 cm) and healthy shoots were rooted (12.0 ± 0.10 roots per shoot) on half-strength MS medium fortified with 9.84 mM of indole-3 butyric acid (IBA). The in vitro regenerated plantlets were hardened in the greenhouse and transferred to the field. Significant developmental changes were observed in the foliar micromorphology of in vitro raised plantlets when these were transferred to the field. The stomatal index was gradually reduced (26.72 to 21.25) in the leaves from in vitro to field environments. But, vein-islets and veinlet terminations (13.4 and 7.6) were increased (39.7 and 18.4) respectively from in vitro to in vivo grown plants. Simple, unicellular, less frequent and underdeveloped trichomes were observed with the leaves of in vitro plants but fully developed trichomes recorded in the field transferred plants. The study could help in understanding the response and adaptation of tissue culture raised plantlets towards changed environmental conditions.

The low availability of soils with an appropriate pH value (4.2-5.2) is a factor limiting an increase in highbush blueberry acreage. The experiments examined the influence of a physiologically acidic urea phosphate fertilizer on the pH change of the soil and the mineral content in the soil, leaves, and fruit as well as polyphenols in the fruit of two highbush blueberry cultivars – ‘Sunrise’ and ‘Brigitta Blue’. The fertilizer, at doses of 30 and 60 kg of nitrogen per hectare, was used in the experiments in each of the three years of the study.

After using 60 kg N ha⁻¹, urea phosphate caused a reduction in soil pH. It also significantly influenced the total soil nitrogen content – the average for the cultivars was 7.40 mg in 2015, while in the control plots – 1.85 mg 100 g⁻¹. These quantities are above the optimum recommended for highbush blueberry. At the same time, low amounts of this ingredient were found in the leaves (‘Sunrise’ – 1.83 mg; ‘Brigitta Blue’ – 1.77 mg 100 g⁻¹).

Even after the application of 30 kg of fertilizer in the second year, the phosphorus content in the soil was at a high level (> 4 mg 100 g⁻¹). The amount of phosphorus also increased in the leaves and fruit. Despite considerable quantities of available magnesium in the soil after urea phosphate application, a significant reduction of this component was observed in the leaves and fruit compared to the unfertilized control bushes. The applied fertilizer reduced the amount of polyphenols in the fruit of the tested cultivars.

Gladiolus is one of the most important lucrative cut flower crops that is commercially cultivated worldwide due to its various spike forms, size, and shape and color combinations. In order to further increase the commercial and horticultural value by improving the ornamental traits of gladiolus ‘White Prosperity’, polyploidy was induced by soaking gladiolus corms in different colchicine concentrations (0.1%, 0.2% and 0.3%) for 24 h. Different colchicine concentrations had a little effect on sprouting and survival percentage but it significantly delayed the emergence of sprouts. About one third decreases in plant height along with reduction in number of leaves per plant, leaf area, length and width, chlorophyll content, diameter and number of cormlets per corm was observed in treated plants. Colchicine at 0.1% concentration improved the ornamental value of gladiolus by increasing vase life whereas colchicine at 0.3% was effective in increasing floret diameter. However, the colchicine treated plants exhibited delayed and reduced percentage of flowering corms. Pollen and stomatal study was done for the identification of polyploidy and it showed that both pollen and stomata size were increased while stomatal density and pollen fertility was significantly reduced in polyploid plants. Induction of polyploidy (mixoploids + octoploids) was achieved in all concentrations, however 0.2% and 0.3% concentrations of colchicine were effective for producing large number of polyploid plants. But at 0.1% concentration of colchicine, majority of plants did not show any change in their original ploidy level (tetraploid). These putative polyploids may be helpful for further improvement in ornamental and horticultural value of gladiolus.

The demand for organically grown products is increasing because many people are concerned about the environment and believe that organic products are healthier than conventional ones. Some studies have shown that organically produced tomato fruits contain higher levels of antioxidants, polyphenols and carotenoids than those produced conventionally. The objective of this study was to evaluate the influence of organic and inorganic fertilization on agronomic and quality characteristics of the processing tomato. The 2-year experiment was laid out in a randomized complete block design, with three replications and three fertilization treatments (untreated, compost and inorganic fertilizer). The results showed that the highest fruit number per plant (98.5), average fruit weight (63.6 g) and fruit yield (168.0 t ha⁻¹) were obtained under inorganic fertilization. The highest total soluble solids (4.39 °Brix) and total soluble solids to titratable acidity ratio (17.4), L* (43.4) and a* (35.4) values, as well as the highest lycopene content (88.5 mg kg⁻¹ f.w). were achieved through the application of organic fertilizer. Significantly higher total soluble solids and total soluble solids to titratable acidity ratio in organically grown tomatoes are particularly important to the processing tomato industry. Finally, the highest lycopene content produced under organic fertilization as well as the non-significant difference between the organic and conventional tomatoes in terms of lycopene yield make organic processing tomatoes suitable for lycopene production.

Corchorus olitorius (L.) is one of the main crops for fibre production, cultivated in tropical and subtropical environments, from Africa to Japan, across the Middle East and India. In developing countries, the leaves are used as a medicine and also as food. In this study, we evaluated the physiological responses of nine accessions of C. olitorius in order to nominate the most suitable one for introduction into southern Europe. African and Asian accessions obtained from the Leibniz Institute IPK gene bank were analysed for their photosynthetic variables and quality traits during cultivation. Accessions from Africa, in particular those from Egypt and Libya, showed higher intrinsic water-use efficiency. However, at high temperatures, the Japanese accession also showed a high level of water-use efficiency, as evidenced by the high carbon fixation rate. Chinese and Indian accessions showed a reduction in growth performance, although a high concentration of antioxidants in the leaves and biomass accumulation have been reported in those accessions. C. olitorius demonstrated an intrinsic attitude to adaptation; according to their subtropical origin, all of the plants grew at sub-optimal status (Fv/Fm). These data, however, do not seem to compromise the potential of these plants as a crop for growing in southern Europe. Moreover, their introduction can be based solely on their biochemical quality traits.

The cost of growing triploid watermelon seedlings has increased due to their low-efficiency grafting. The first priority in growing seedless watermelon seedlings is increasing the grafted-plant and seed-utilization rates. This study aimed to improve the grafted-plant rate by screening the most suitable substrate formulation, optimizing water moisture in the substrate, and evaluating the effect of different scions to improve seed-utilization rate. Five combinations of substrate (S1 to S5) and seven relative humidity levels (45%, 50%, 55%, 60%, 65%, 70%, and 75%) were used. Three types of scions (yellow bud, Ts-1; two cotyledons did not unfold, Ts-2; and first true leaf appeared, Ts-3) were tested. Results showed that the combination of S1 exhibited the best seed-utilization rate which was 71.6%. Moreover, the most suitable water moisture in the substrate ranged from 50% to 55%. The usage of the scion from Ts-3 significantly increased the grafting survival, grafted plant and seed-utilization rates by 13.7%, 10.1% and 22%, respectively, compared with the conventional method. Our study suggested that the best time to use the scion and the rootstock was during the seedling stage when the first true leaf unfolded. The proposed method decreased the production cost of seedlings and significantly improved the efficiency of grafting procedures. The results of this work are applicable to the technique of growing seedlings and can thus guide growers of high-quality grafted plants of triploid watermelon.

This study aimed to investigate the effects of drought stress on Amsonia orientalis, an endangered ornamental plant with a limited natural distribution in Europe. Effects of polyethylene glycol (PEG)-mediated drought stress (-0.15, -0.49, -1.03 and -1.76 MPa osmotic potentials) were tested on in vitro cultures. In general, root lengths and numbers, total protein, chlorophyll a and carotenoid contents were negatively influenced at elevated levels of the stress factor. The successive decrease in the tested osmotic potentials resulted in gradually higher H₂O₂, malondialdehyde (MDA) and proline contents. Activities of the antioxidant enzymes, peroxidase (POD) and catalase (CAT), were found to be enhanced in response to the decreasing osmotic potential tested, whereas increased superoxide dismutase (SOD) activity was observed at the -0.15 MPa osmotic potential. Strong activation of POD enzymes under drought stress suggests that POD enzymes might have a major role in regulating the H₂O₂ content, while CAT has only a supplementary role in A. orientalis. These results indicated that although A. orientalis is susceptible to long-term drought, the species may survive during mild drought stress because the development of the plant was not totally inhibited but only limited. Nevertheless, the species should be introduced to well-irrigated lands, after evaluation of the soil’s water status, in order to ensure the continuation of its generations.

Research was carried out in northern Europe (Russia) with the purpose of assessing the yield, quality, biologically active compounds and elemental composition of Physalis angulata and Physalis pubescens fruits. P. angulata cultivars ‘Konditer’ and ‘Konditer 2’ gave the highest yield and mean fruit weight (11.2 t ha⁻¹ and 75 g, on average), whereas P. pubescens variety Zolotaya Rossip had the worst outcome as it produced the smallest berries (3 g). ‘Zolotaya Rossip’ fruits attained the highest values of dry matter and soluble solids, while ‘Violet’ and ‘Korolek’ the highest polyphenol and ascorbic acid concentrations, respectively. Organic acid composition of Physalis fruits revealed high varietal differences and predominant accumulation of tartaric and malic acids. Positive correlations were recorded between dry matter and polyphenols, as well as between Fe and Mn, but an adverse correlation between Si and Cd content. Physalis fruits showed to be a good source of beneficial compounds for human beings, such as polyphenols and ascorbic acid, as well as mineral nutrients, i.e. K, Mg, P, B, Co, Cu, Fe, Li, Mn, Si, V and Zn.

A research was carried out in southern Italy in order to evaluate the effects of two farming systems (open field, greenhouse) and five transplanting times (27 September, 11 October, 25 October, 8 November, 22 November) on plant growth, harvest precocity, fresh pod yield and seed quality of organic faba bean. Crop biomass and root expansion were higher in open field than in greenhouse. The fourth planting time resulted in the highest crop biomass, whereas the second crop cycle showed the highest leaf area index. Greenhouse crops showed higher precocity than the open field ones by about two weeks, as well as the first transplant; the delay in harvest beginning increased from the second to the fourth planting time. Both fresh pod and seeds yield were significantly higher in open field than under protected environment with the third and fourth planting times. Seed fiber and protein content showed higher values in greenhouse compared to open field and increased with the transplant delay. Seed polyphenols attained higher concentration in open field and with the two earliest planting times. Overall, 25 October to 8 November planting times in open field best fitted the southern Italy growing conditions in terms of pod yield, but the 27 September to 11 October planting times resulted in the highest harvest precocity, remarkably enhanced under greenhouse growing, whereas seed quality was controversial.